1. Field of the Invention
The present invention relates to a device for filling a reservoir of a fuel supply module, in which a fuel feed unit is surrounded, e.g., by a container to be filled, and to the fuel supply module and fuel supply system containing that device.
2. Prior Art
A device for feeding fuel from a supply container or reservoir to an internal combustion engine of a motor vehicle is described in DE 195 49 192 A1. The fuel feed unit is connected on its low-pressure side with the supply container and on its high-pressure side with the internal combustion engine. The internal combustion engine has a fuel return line, which leads to a jet pump arranged near the tank bottom. This jet pump feeds the excess fuel back into the supply container from the return line through a mixing region in the supply container. The fuel feed unit takes the fuel from the supply container. A siphon-like mixing region is provided between the supply container and the tank bottom, which has an opening in a transitional region to the supply container, which is closable with a closure element.
The closure element is mounted in a guide of a filter element by means of a longitudinally movable pin. Under certain circumstances, such as a low fuel level in the fuel tank the fuel level is no longer sufficient to open a heavy closure element. Thus filling of the supply container cannot occur. As a result, starting problems occur. If the closure element sticks in its guide, fuel can slowly leak from the supply container, which can lead to an emptying of the container and similarly can cause starting problems.
It is an object of the present invention to provide a device for filling a reservoir of a fuel supply module of the above-described kind, which does not suffer from the above-described disadvantages.
It is another object of the present invention to provide an improved fuel supply module and fuel supply system including the device for filling the reservoir according to the invention.
According to the invention the device for filling the reservoir of a fuel supply module, which is connected on its low-pressure side with an interior of a fuel tank and on its high-pressure side with an internal combustion engine, the reservoir including a fuel feed unit and provided with an opening in a lower portion thereof, includes a movable closure element arranged in the reservoir in the lower portion of the reservoir and a float element arranged in the reservoir and connected with the movable closure element to close the opening or to open the opening in the lower portion of the reservoir according to a fuel level in the reservoir.
In the device for filling the reservoir of the fuel supply module according to the invention the closure element does not stick in a guide, so that the filling of the reservoir takes place without failure because of a sticking filling valve. The hydrostatic pressure acting on a preferably umbrella-shaped closure element in the filled reservoir provides a satisfactory sealing of the opening at the base of the reservoir, so that gradual emptying of the reservoir when the fuel level in the tank is low does not occur. Optimum operation of a primary filling valve and a reliable seal of the reservoir from the outside is guaranteed by the structure of the apparatus according to the invention. Thus it is possible to start the motor vehicle each time, since both a sealing of the reservoir to prevent it from slowly running empty and also an unhindered fuel flow into the reservoir is guaranteed when the level of fuel in the tank is low.
In an advantageous embodiment of the invention the closure element and the float element are arranged on a common pivoting lever arm. Easy operation of the resulting filling valve formed in this way is guaranteed by balancing the torque about the pivot point or rotation axis of this common lever arm. The common lever arm is pivoted about a somewhat elevated rotation axis so as to open and close the valve.
In an especially preferred embodiment the closure element, which is operated by means of the float element, can be formed by an umbrella-shaped valve cover. It has a surface that is gently curved in order to distribute the hydrostatic pressure uniformly and sit on the valve seat, thus providing a tight closure of the opening. The float element and the closure element are advantageously located on opposite ends of the common lever arm.
In a particularly preferred embodiment of the closure element it can be attached to the common lever arm by means of an adjustable attaching element, which guarantees a precise adjustment during the first assembly of the fuel supply module. The float element can be attached to the common pivoting lever arm, so that it is pivotally mounted on the lever arm so that it can be level with the fuel level in the reservoir.
The device for filling a reservoir of the fuel supply module can advantageously be provided in a fuel supply module, which is part of a fuel supply system for the internal combustion engine.